Technically the attorney is right...in order to force this, an interpleader would be appropriate.
That said, I suspect it will cost over $1000 to hire a lawyer to resolve this. That would make no sense...that is, it would make no sense to hire a lawyer if you have to pay more to resolve this than you can expect to receive as a result of the suit.
That said, there may be a way to address this.
I would consider small claims
Small claims is a true "peoples court". The formal rules of evidence and procedure do not apply. So you can represent yourself (no need to hire a lawyer).
The process is simple enough. You head to the county court (the county where the property is located) and talk to the clerk of the court. They can get you the forms needed to start. You file the claim, serve a copy on the defendant and wait for your day in court.
In court, be prepared to tell the judge what happened, and bring in copies of any evidence that supports your case. IF there are witnesses who can testify about what happened? Have them come as well.
Again, technically the way to address this is with an interpleader action. But because of the informal nature of small claims it may well be the court rules in your favor.
So I would go the small claims route to try and resolve this yourself.
Please let me know if you have more questions. I am happy to help if I can. Otherwise, please rate the answer so I may get credit for my work.